[U-Boot] [PATCH] net: phy: micrel: add an option to disable gigabit for the KSZ9031

[Joe Hershberger]

On Fri, Jul 28, 2017 at 2:59 PM, Sebastien Bourdelin
<sebastien.bourdelin at savoirfairelinux.com> wrote:
> The environment variable "disable_giga" can now be used to disable
> 1000baseTx on the Micrel's KSZ9031.
>
> Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin at savoirfairelinux.com>

Other than one nit below...
Acked-by: Joe Hershberger <joe.hershberger at ni.com>

> ---
>  drivers/net/phy/micrel.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index 0e4a4ebcc6..eeeba3c232 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -491,12 +491,39 @@ static int ksz9031_phy_extwrite(struct phy_device *phydev, int addr,
>  static int ksz9031_config(struct phy_device *phydev)
>  {
>         int ret;
> +       unsigned features;
> +       unsigned bmcr = 0;

Seems better to define these in the block where they are used and
inconsistent initialization is odd. Neither need init since they are
assigned as first use.

> +
>         ret = ksz9031_of_config(phydev);
>         if (ret)
>                 return ret;
>         ret = ksz9031_center_flp_timing(phydev);
>         if (ret)
>                 return ret;
> +
> +       /* add an option to disable the gigabit feature of this PHY */
> +       if (getenv("disable_giga")) {
> +               /* disable speed 1000 in features supported by the PHY */
> +               features = phydev->drv->features;
> +               features &= ~(SUPPORTED_1000baseT_Half |
> +                               SUPPORTED_1000baseT_Full);
> +               phydev->advertising = phydev->supported = features;
> +
> +               /* disable speed 1000 in Basic Control Register */
> +               bmcr = phy_read(phydev, MDIO_DEVAD_NONE, MII_BMCR);
> +               bmcr &= ~(1 << 6);
> +               phy_write(phydev, MDIO_DEVAD_NONE, MII_BMCR, bmcr);
> +
> +               /* disable speed 1000 in 1000Base-T Control Register */
> +               phy_write(phydev, MDIO_DEVAD_NONE, MII_CTRL1000, 0);
> +
> +               /* start autoneg */
> +               genphy_config_aneg(phydev);
> +               genphy_restart_aneg(phydev);
> +
> +               return 0;
> +       }
> +
>         return genphy_config(phydev);
>  }
>
> --
> 2.13.3
>
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